Ceramic ware dryer and preheater and method



April 19, 1960 w. L. HANLEY CERAMIC WARE DRYER AND PREHEATER AND METHODFiled May 28, 1957 2 Sheets-Sheet 1 April 19, 1960 w. L. HANLEY CERAMICWARE DRYER AND PREHEATER AND METHOD Filed May 28, 1957 2 Sheets-Sheet 2INVENTOR.

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CERAMIC WARE DRYER AND PREHEATER AND METHOD William L. Hartley,Greenwich, Conn.

Application May 28, 1957, Serial No. 662,278

2 Claims. (Cl. 34-213) This invention comprises improvements in methodsof drying and preheating green molded ceramic ware such as brick, tileand the like in preparation for its introduction into a kiln and in adryer and preheater by means of which such methods may be practised.

One object of the invention is to provide an improved form of dryer andpreheater mechanism for freshly molded green ceramic ware by means ofwhich the required amount of moisture can be rapidly and efficientlyremoved from and the ware preheated with a minimum expenditure of powerand heat energy.

Another object of the invention is to provide a novel form of apparatusfor these purposes, constructed and arranged to effect efficientmovement of the hot air used for drying and preheating purposes and theremoval of the relatively cooler moisture laden air after it hasperformed its drying function.

Another object of the invention is to provide an apparatus of this kindin which the humidity in the dryer can be controlled to insure thecorrect drying cycle for such ware.

A more specific object of the invention is to provide a dryer andpreheater construction arranged so that the motor driving mechanism forthe fans which circulate thefdrying air is kept relatively cool and ismade readily accessible for maintenance without interrupting theoperation of the dryer.

Other and more detailed objects of the invention involving the structurewill be apparent from the following description of the form thereofillustrated in the attached drawings.

Still another object of the invention is to provide novel methods ofoperating dryers and preheaters of this type to insure the maintenanceof proper humidity conditions within the device to facilitate overallefiicient operation and the production of properly dried ware.

In the accompanying drawings,

Figure l is a typical vertical cross-sectional view of a dryer andpreheater in accordance with this invention, taken for example, on theline 1-1 of Figure 2;

Figure 2 is a composite view of the dryer and preheater of Figure 1showing the construction at different vertical levels, the lefthandportion of the view being a top plan view; and

Figure 3 is a front elevational view of the dryer and preheater. i

As is well known in the art of manufacturing of brick, tile and similarceramic ware, such ware is first molded to shape in a relatively wetcondition. It is then stacked on cars and placed in dryers where it issubjected to hot gases which dry the ware to the state where it is readyfor introduction into the preheater section of a firing kiln. As is notunusual in this art, the hot gases used for drying the green ware arewithdrawn from some other portion of the process such as for examplefrom the firing section of the kiln.

It will be apparent as the disclosure proceeds that it Patented Apr. 19,1960 lad is unimportant from what source the hot gases are obtained.However, in order to insure eincient use of as much as possible of theheat energy involved in the heating of ceramic ware, it has been foundthat the hot gases which are withdrawn from the firing section of thekiln, and in some cases from the preheater section, have suflicientavailable heat to make them useful in drying and preheating the greenware.

The device of this invention is constructed and arranged so that theware can be heated to considerably higher temperatures than hasheretofore been practised in the drying of green ware in preparation forits introduction into the preheater of the brick kiln. The parts are soarranged that the ware can be dried and brought rapidly to aconsiderably higher temperature so that upon introduction into thepreheater of the kiln it can progress therethrough more rapidly,providing a general overall increase in output.

As illustrated in the drawings, the dryer and preheater includes afooting and foundation 10, made of any material suitable for thepurpose, and commonly of brick. The peripherial outline of thefoundation can vary, but as illustrated it is generally rectangular.Erected upon the foundation are side and end walls 12 and 98, all ofwhich may be composed of brick or concrete work, and preferably, asillustrated for the side walls, be of the double wall construction toprovide a dead air insulating space therebetween.

The roof of the structure can be in the form of a flat arch l4 andlikewise constructed of suitable material such as a reinforced concreteslab. As is clearly illustrated in the various figures the end walls 98of the housing are open at the center and at the ground level to form anopen ended tunnel extending all the way through the housing. This tunnelis formed by a low ground level foundation in the form of a reinforcedconcrete slab Z2 and serves as a support for a pair of Walls 20-24 whichdefine the space forming the tunnel. In other words, the end walls 98are open in alignment with the tunnel S1 which thus results.

Extending transversely across between the side walls and below the fiatarch 14, are a series of reinforcing angle irons 16 which areinterconnected with a series of vertical angle iron supports 18 to forman interior open framework upon which the internal parts of thestructure are mounted, as will be explained below.

Mounted on the two central rows of vertical, angle irons 3.3 are thevertical walls which are provided with a series of pairs of alignedopenings 42 which are preferably framed by reinforcing angles as shown.The outer walls 12 and the vertical walls 34 form a pair of parallelmain ware treating tunnels. Extending between the walls 345 is ahorizontal wall 49 having a series of large circular central openings aswhich are respectively aligned with each pair of openings 4-2. Thehorizontal Wall 4!) divides the central space between the walls 34 intoa pair of longitudinally extending chambers .53 and S4, the former beingabove the latter.

Extending longitudinally through the chamber S4 is a baffie wall 43which is constructed of a series of gen erally Ushaped angle ironsembedded in a heat resistant reinforced covering which may be made ofcommercialiy available insulating cements. This generally V-shapedbafile Wall forms below it the tunnel S1, isolating that tunnel from thespace 84 The battle wall 58 runs all fthe way from the front end to theback end of the housing extends to that source or to several sources.

At this point it may be noted that the chambers S3 and S4 are closed bythe end walls 98 of the housing, with the exception that each end wallhas an access door 100, as shown in Figures 1 and 3. The chambers S2 areprovided at each end with doors, not shown, by means of V -which thecars C may be introduced thereinto and re- 'moved'therefrom. These carsride on rails R, which are mounted at ground level at the bottom of thechambers S2. At this point it may be noted, as diagrammaticallyillustrated, that the freshly molded green ware is stacked on thesecars, usually in the form of two laterally spaced stacks WS, to formfree spaces around the top and the ing drive shaft 52 journaled in thebearings 50 and extending through an opening 58 in baiile wall 48. The

opening 58 is large enough to permit free flow of air around the shaft52. Mounted on the upper end of the shaft 52 is a propeller assembly 56,which is positioned in the opening 46 of the wall 40. It will be notedthat there is one of these propellers with its drive stationed at eachof the openings 46, and hence each of a pair of associated openings 42.The number of such assemblies will vary, of course, with the length ofthe dryer and the structure is dimensioned so that when the dryer isfull of cars there will be two cars with their stacked ware stationedlaterally opposite each of the propellers 56.

Supported on the fiat arch 14 of the dryer are a series of conduits 64and 68 laterally and longitudinally spaced along the dryer housing. Theconduits 64 open into the spaces S2 at the top. Each of the conduits 64,68 is provided with dampers 66 and 7 respectively. The conduits 64 and68 connect respectively with longitudinally extending header ducts 60and 62, which either extend to a common connection which in turn extendsto the source of hot dry gases, or each of which individually Theheaders 60 and 62 provide the main hot gas supply conduits for thedryer. Distributed along the top of the housing so as to be individuallyvertically directly above the propellers 56, are a series of exhaustduct branches 76 which open directly into the space S3 which extendsthroughout the length of the dryer housing. Each of the branches 76 isprovided with a damper '78 and all of them are connected with a mainexhaust header 72. The exhaust header 72 is provided with a main stack74 through which the relatively cool gases are discharged to theatmosphere after passing through the dryer.

The method of operating this dryer takes cognizance of the fact that thecars C with the green molded ware stacked thereon in lateral andlongitudinally spaced stacks WS to form spaces between and around themare pushed in end to end relation into the housing from one end andremoved from the housing at the other end, along the rails R. Assumingthat the dryer has been in operation so that each of the drying tunnelsS2 is completely occupied with cars C, it is apparent that the waregoing in the entrance end will contain the most moisture, while the wareleaving the exit end will be dried and heated to the required degree. Inthe usual practice the cars are moved through the dryer and preheaterintermittently, with periods of rest when the doors, not shown, in bothends of the tunnels S2 will be closed. Hot gases from any suitablesource, including the firing zone of a brick kiln, as previouslysuggested, are supplied under pressure into the ducts 60 and 62. Thehottest gases are supplied into the ends of these tunnels adjacent theexit end of the dryer and portions thereof are directed from the mainduct 60 and 62 into the circulating path comprising the compartments S2,S3-, and S4, at the. sides, and at points distributed longitudinallyalong the housing from one end to the other, through the respectivebranch ducts 64 and 68.

Each of these ducts is provided with a damper, as illustrated at 66 and70, so that controlled amounts ofthe hot gases can be discharged intothe circulatory paths at points along their length, that is from one endof the housing to the other. These hot gases circulate within thehousing, as shown by the arrows, so as to move downwardly, for example,from the branch 64 into the space S2, into contact with the sides andtops of the stacks WS. After picking up moisture from the stacks, thisair passes through the large openings 42 into the space S4 and areimpelled by the propellers 56 upwardly into the space S3, which extendsthroughout the length of the housing as do the spaces S2. Much of thesegases then follow the arrows, as shown, back into the spaces S2. Thus itcan be said that the blanket of hot gases is caused to circulate throughthe drying and heating tunnels S2 aided by the propellers 56..

Controlled portions of these circulating blankets are withdrawn throughthe branches 76 into the exhaust header 72 and from there by way of thestack 74 to the atmosphere. Each of the branch ducts 76 is provided withan adjustable damper 78 so that'the proportion of moisture ladenrelatively cooler gases withdrawn thereat can be controlled. It follows,therefore, that both the temperature and the moisture content of thegases circulating in the blankets around the drying tunnels can beadjusted by means of the dampers 66 and 78 in 76 and 68 to effect thedrying and preheating of the green ware at the best rate and to theproper final moisture con- 7 tent for the ware.

Thus by these multiple controls it is possible to gradually extract themoisture from the greenest ware as it progresses from the entrance tothe exit end of the housing, so that when a car C is pushed out of theexit end the ware stacks WS will be dried and heated to the properextent which experience has demonstrated to be the best, and in additionthe ware will be at a temperature suitable for immediate introductioninto the preheating section of the main firing kiln.

An important feature of this invention is the provision of what might becalled maintenance tunnel S1, extending from one end of the housing tothe other, and of' a height to provide headroom for a maintenance man,giving him ready access to the motor drives and bearings for thepropellers 56.

Another important feature of this arrangement results from the fact thatthe maintenance tunnel S1 is open at both ends and the rotatingpropellers 56 are permitted to draw fresh air from the tunnel S1 throughthe relatively large openings 58 .around the motor shafts 52, and ofcourse, over the motors 54 and bearings 50. Thus, this equipment inaddition to being readily available for the necessary maintenance, iskept relatively cool and substantially out of direct contact .with thehot gases circulating within the dryer. It will be understood, ofcourse, that the roof or hood for the tunnel S1 extends through.- outthe length of the dryer.

It will be noted by reference to the drawings that the driving mechanismfor the fans 56 while generally aligned with the take-off branches 76are mounted at the bottom of, in the region of, or at a level towardsthe bottom of the main tunnels S2. The baffle wall 48 with the enlargedopening 58 for the shafts 52, makes it possible for the fans 56 to drivecool air from the tunnel S1 over the driving equipment for the fans,keeping them below dangerous operating temperatures. In other words,this driving equipment instead of being in the path of the hot gases iscompletely out of that path and arranged to be included in the coolingair path in a very simple way and at the same time making the drivingequipment readily available for maintenance.

In view of the above description it will be apparent to those skilled inthe art that the subject matter of this invention is capable ofconsiderable variation in its details of construction involving featureswhich are not of prime importance to the novel subject matter hereindisclosed. It is preferred, therefore, that the example illustrated anddescribed herein not be considered in a limiting sense, and that thescope of protection afforded by this patent be determined by the claims.

What is claimed is:

1. A device of the type described comprising a housing having aninterior wall structure to form two laterally spaced drying chambers anda central chamber lying therebetween, said central chamber beingadjacent to and substantially longitudinally coextensive with saiddrying chambers, means for supplying hot gases into said drying dhambersat a number of points along the length thereof, means for withdrawinggases from said central chamber along a number of points distributedtherealong, a baflie wall extending along said central chamber to form amaintenance tunnel, a further wall having fan openings extending alongsaid central chamber above said baflie wall, the walls of said dryingchambers having air passages opening into the space between said bafliewall and said further wall, said baflle wall and said further wall beinghorizontal, extending substantially across said central chamber andbeing supported from. the side walls thereof, and motor driven fansmounted in said fan openings having their power drive mounted in saidmaintenance tunnel and connected to respective fans by drive shaftsextending through said bafile wall.

2. In the combination of claim 1, said balfie wall having air passagesaround said shafts passing therethrough.

References Cited in the file of this patent UNITED STATES PATENTS553,723 Proctor Jan. 28, 1896 1,451,589 Schwartz et a1. Apr. 10, 19231,513,932 Rhoads Nov. 4, 1924 l,567,023 Larsson Dec. 22, 1925 1,840,523Mueller Jan. 12, 1932 1,841,927 Allsop Jan. 19, 1932 2,085,634 Cobb June29, 1937 2,758,388 Westerberg Aug. 14, 1956 FOREIGN PATENTS 521,005Germany Mar. 18, 1931

